Coolant level and topping up

[rawbhp]

I'm off to a Car Limits day tomorrow and checked my coolant just now when I got back in. Hot engine, but it was right on the min level. Does this mean it will be low when cold too? Can I top it up with water until I can get some coolant?

[Ekona]

If you must then use ionised water at least, not tap crap. Tbh that bottle is only an overflow reservoir, keep an eye on it over the day and just get some coolant from Nissan when you get a chance.

[ZMANALEX]

Check and top up only when cold